I've seen that happen a few times to a guy I work with. I don't think he has ever managed to fix it. You could try merging the old scene into a new but I'm pretty sure he tried it and it failed. Save in iteration and check your autoback files. =/
Thanks for everyones responces! All of my previous iterations are like this (the one with just one edit poly is like this aswell). They were saved this way, and then I continued to work on them with none of these effects present. I should have colapsed the stack at least to the first edit poly on it (if I use symetry I…